Coton is also on iPad: http://itunes.apple.com/app/id509851679
/! Only available in English and French!

Coton is a beautiful cloud identification app for your iPhone and iPod Touch.

Identify clouds by browsing stunning pictures and detailed descriptions of all the different types of clouds you may spot. Coton relies on the International Cloud Atlas classification, the authoritative book from the World Meteorological Organization.

Learn about cloud types and their corresponding weather forecast including chances of rain and storm. Try to figure out the weather of the day, just by looking at the sky!

Coton includes:
- 33 cloud index cards for the main cloud genera, species, varieties and special clouds
- a gallery containing more than 120 awesome pictures
- an illustrated guide which simply explains what is a cloud and how clouds are classified
- a chart of the 10 cloud genera
- a setting allowing you to switch between metric and imperial measurement system

The only thing you'll have to do is looking up... Enjoy your spottings!
Just remember: "It is rare that a cloud gets the shape of a cloud." Ylipe